Referring to FIG. 6 of Japanese Unexamined Patent Application Publication No. 2000-16233, an airbag device is disclosed. Specifically, such an airbag device detects the distance between the body of an occupant in a seat and an instrument panel with, for example, an infrared sensor. If the detected distance is less than a predetermined value, a gas generator in the airbag device is prevented from operating even during a collision, or the deployment force of the airbag is reduced.